HEAL1000 Lecture 5: Friction, energy, work and power
Document Summary
Muscle produces a force but does not change length: concentric. Muscle produces a force and shortens: eccentric. A kinetic chain consists of a system of segmental links contributing to a movement (some movements have both components) Closed kc- when the most distal segment is fixed (plank-hand or foot fixed on ground or object: work multiple muscles and joints, decreased shear forces, more functional, greater muscle co-contraction. Kinetic chain-segmental sequencing-summation of forces/velocities: where body parts are moved in sequence to generally produce maximal force or velocity, typically used in whole body actions (throwing, kicking) Generating motion: n 3rd law-for every action there is an equal and opposite reaction, n 2nd law-f=m. a. The greater the mass and the greater the acceleration, the greater the force. As you transfer momentum to lighter segments the velocity increases: momentum generated at the proximal end of the chain.
